The parenteral administration, including intravenous administration of a beneficial agent is commonly used in clinical practice. Presently, the beneficial agent is administered using a parenteral delivery system that contains a premixed formulation comprising a parenterally administrable fluid and the agent. The premixed formulation is administered from a container suspended above a patient. While this form of parenteral administration is widely used and often leads to successful therapy, there is still a great deal of dissatisfaction with this type of parenteral delivery system. For example, with the parenteral systems now in use, the agent is premixed with the fluid and this frequently requires storing the parenteral system at a lower temperature to prevent degradation of the beneficial agent. Also, beneficial agents that are fluid sensitive and require formulation with the solution at the time of administration, cannot be administered with these prior art systems.